The field of the disclosure relates generally to systems and methods for managing loads in a gearbox and, more particularly, to an apparatus and method for managing pinch loads on a planet gear with journal or fluid film bearings.
Aircraft engines typically include a fan, a low pressure compressor, and a low pressure turbine rotationally coupled in a series configuration by a low pressure shaft. The low pressure shaft is rotationally coupled to the low pressure turbine and a power gear box. The power gear box includes a plurality of gears and is rotationally coupled to the low pressure fan and low pressure compressor. The gears include a gear rim surrounding a journal bearing or fluid film bearing. The journal bearing includes a pin surrounded by a fluid film. The fluid film allows the gear rim to rotate around the stationary pin. Aircraft engines may generate significant torsional loads on the low pressure shaft. Torsional loads on the low pressure shaft can exert torsional forces on the gears within the power gear box. Additionally, these torsional loads transferred through the planet gears may exert unevenly distributed loads on the journal bearings within the gears. These unevenly distributed loads result in pinching the pin with the gear rim which will induce higher contact stresses between the gear rim and the pin and reduce the reliability of the journal bearings as well as the power gear box.